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Overscan on DVB-T - UE32H5000

Posted: Fri Jul 17, 2015 6:50 pm
by TedT
Hello,

I have an interesting problem with my UE32H5000 TV. I'm having an issue with the overscan on the top being too much, such that the tops of channel logos are cut off (which would be visible on other TV sets).

The issue is only present on SD channels (576i), and doesn't seem to affect HD (1080i) channels. It doesn't affect HDMI input, nor does it affect graphics rendered by the TV (e.g. menus, DVB Teletext).

I've accessed the service menu (Info, Menu, Mute, Power) but don't seem to find any settings that apply to picture geometry.

Just wondering if anyone has any suggestions?

Thank you :)

Re: Overscan on DVB-T - UE32H5000

Posted: Fri Jul 17, 2015 10:44 pm
by zoelechat
TV systematically perform overscan on 576i to fit panel resolution, consequently cropping image to 540 lines (=1080/2). So, the question is whether you really have abnormal OVER-overscan, or simply expected top-bottom missing 36 (=18*2) lines?

Re: Overscan on DVB-T - UE32H5000

Posted: Sat Jul 18, 2015 1:02 am
by TedT
Hello, thanks for the reply.

It is definitely abnormal. Compared to both a Panasonic and an LG viewing the same channels, much more is chopped off the top on the Samsung. It is consistent across all 576i channels, but 1080i channels look the same as the two other TVs.

Is there a setting to adjust this? :)

Re: Overscan on DVB-T - UE32H5000

Posted: Sat Jul 18, 2015 9:08 am
by zoelechat
TedT wrote:Is there a setting to adjust this? :)
I don't think so. 18 lines can seem not that much but if you apply cropped offset to whole image you have (720*576)/(675*540)-1=near to 14% image loss !! See the huge difference, especially around channel logo, and even unforeseen black borders there (both captures are untouched TV screenshots):
20150718094736_MEDIA.jpg
20150718095028_HDMI1.jpg
576vs540.jpg
That's how it goes on Samsung TVs. My former LG also had some "fit to screen" option on SD sources... Just don't compare rendering from different brands, and watch only one TV at once ;)
And again that's expected to occur only on SD/576, no need to "fit" 1080 to 1080 :)

Re: Overscan on DVB-T - UE32H5000

Posted: Sat Jul 18, 2015 12:39 pm
by TedT
Hi zoelechat,

Thanks for that information. This got me curious and I checked using a screen grab of the DVB-T channel where this is most noticeable, acquired with VLC. I'm loosing 23 pixels from the top of the frame, and about 18 from the bottom of the frame. Shame it can't be adjusted. I must pay more attention next time I buy a TV. :D

Re: Overscan on DVB-T - UE32H5000

Posted: Sat Jul 18, 2015 12:59 pm
by zoelechat
I must admit I was a bit disappointed at the beginning too, especially because even in "Smart view" picture mode (small centered image with big black borders, always wondered what's "smart" there :D), image is still cropped for no reason...
Unfortunately I'm not sure such technical "detail" (=gap) can be found in any datasheet. I guess it must be easier to "align" than to do *real* scaling potentially producing uncertain result. It's just one amongst few imperfections we spend our time on trying to fix them. Still found no clue about this one though :)